Effectiveness of intensive stand-alone smoking cessation interventions for individuals with diabetes: A systematic review and intervention component analysis

INTRODUCTION Tobacco smoking poses a significant threat to the health of individuals living with diabetes. Intensive stand-alone smoking cessation interventions, such as multiple or long (>20 minutes) behavioral support sessions focused solely on smoking cessation, with or without the use of pharmacotherapy, increase abstinence when compared to brief advice or usual care in the general population. However, there is limited evidence so far for recommending the use of such interventions amongst individuals with diabetes. This study aimed to assess the effectiveness of intensive stand-alone smoking cessation interventions for individuals living with diabetes and to identify their critical features. METHODS A systematic review design with the addition of a pragmatic intervention component analysis using narrative methods was adopted. The key terms ‘diabetes mellitus’ and ‘smoking cessation’ and their synonyms were searched in 15 databases in May 2022. Randomized controlled trials which assessed the effectiveness of intensive stand-alone smoking cessation interventions by comparing them to controls, specifically amongst individuals with diabetes, were included. RESULTS A total of 15 articles met the inclusion criteria. Generally, the identified studies reported on the delivery of a multi-component behavioral support smoking cessation intervention for individuals with type I and type II diabetes, providing biochemically verified smoking abstinence rates at follow-up at six months. The overall risk-of-bias of most studies was judged to be of some concern. Despite observing inconsistent findings across the identified studies, interventions consisting of three to four sessions, lasting more than 20 min each, were found to be more likely to be associated with smoking cessation success. The additional use of visual aids depicting diabetes-related complications may also be useful. CONCLUSIONS This review provides evidence-based smoking cessation recommendations for use by individuals with diabetes. Nonetheless, given that the findings of some studies were found to be possibly at risk-of-bias, further research to establish the validity of the provided recommendations is suggested.


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Data items 10a List and define all outcomes for which data were sought. Specify whether all results that were compatible with each outcome domain in each study were sought (e.g. for all measures, time points, analyses), and if not, the methods used to decide which results to collect.

4
10b List and define all other variables for which data were sought (e.g. participant and intervention characteristics, funding sources). Describe any assumptions made about any missing or unclear information.

4
Study risk of bias assessment 11 Specify the methods used to assess risk of bias in the included studies, including details of the tool(s) used, how many reviewers assessed each study and whether they worked independently, and if applicable, details of automation tools used in the process.

4, 17
Effect measures 12 Specify for each outcome the effect measure(s) (e.g. risk ratio, mean difference) used in the synthesis or presentation of results.

4
Synthesis methods 13a Describe the processes used to decide which studies were eligible for each synthesis (e.g. tabulating the study intervention characteristics and comparing against the planned groups for each synthesis (item #5)).

Item # Checklist item Location where item is reported
13b Describe any methods required to prepare the data for presentation or synthesis, such as handling of missing summary statistics, or data conversions.

11
13c Describe any methods used to tabulate or visually display results of individual studies and syntheses. 4 13d Describe any methods used to synthesize results and provide a rationale for the choice(s). If meta-analysis was performed, describe the model(s), method(s) to identify the presence and extent of statistical heterogeneity, and software package(s) used.

4
13e Describe any methods used to explore possible causes of heterogeneity among study results (e.g. subgroup analysis, meta-regression).

4
13f Describe any sensitivity analyses conducted to assess robustness of the synthesized results. NA

Reporting bias assessment
14 Describe any methods used to assess risk of bias due to missing results in a synthesis (arising from reporting biases).

NA
Certainty assessment 15 Describe any methods used to assess certainty (or confidence) in the body of evidence for an outcome. NA

Study selection
16a Describe the results of the search and selection process, from the number of records identified in the search to the number of studies included in the review, ideally using a flow diagram.

4-5
16b Cite studies that might appear to meet the inclusion criteria, but which were excluded, and explain why they were excluded.

5
Study characteristics 17 Cite each included study and present its characteristics.

5-9
Risk of bias in studies 18 Present assessments of risk of bias for each included study. 10

Results of individual studies
19 For all outcomes, present, for each study: (a) summary statistics for each group (where appropriate) and (b) an effect estimate and its precision (e.g. confidence/credible interval), ideally using structured tables or plots.

6-9
Results of syntheses 20a For each synthesis, briefly summarise the characteristics and risk of bias among contributing studies. 9 20b Present results of all statistical syntheses conducted. If meta-analysis was done, present for each the summary estimate and its precision (e.g. confidence/credible interval) and measures of statistical heterogeneity. If comparing groups, describe the direction of the effect. NA 24b Indicate where the review protocol can be accessed, or state that a protocol was not prepared. NA 24c Describe and explain any amendments to information provided at registration or in the protocol. NA Support 25 Describe sources of financial or non-financial support for the review, and the role of the funders or sponsors in the review.

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Competing interests 26 Declare any competing interests of review authors. 17 Availability of data, code and other materials 27 Report which of the following are publicly available and where they can be found: template data collection forms; data extracted from included studies; data used for all analyses; analytic code; any other materials used in the review. For more information, visit: http://www.prisma-statement.org/ give up", "gave up", cease*, discontinu*, termin*, "break off", "broke off" TI=( quit* OR stop* OR avoid* OR refrain* OR cessation OR abst* OR "give up" OR "gave up" OR cease* OR discontinu* OR termin* OR "break off" OR "broke off" OR "put an end to" ) OR AB=( quit* OR stop* OR avoid* OR refrain* OR cessation OR abst* OR "give up" OR "gave up" OR cease* OR discontinu* OR termin* OR "break off" OR "broke off" OR "put an end to" ) 3,238,787 S7 S6 NEAR/5 S5 44,364 S8 S4 AND S7 2,095 S9 S3 OR S8 2,103 ABabstracts; AKauthor keywords; NEAR/5 -two or more words within a range of five words from each other; TItitles.